US-A 2006/001384 A1 discloses a LED lamp including bare LED chips and a lamp shade. The bare LED chips are mounted on the outer surface of an axle extending through the lamp shade. The axle accommodates a heat pipe for dissipating heat generated by the LED chips. For this purpose, the heat pipe may be provided with a heat receiving portion and a heat dissipation portion, between which portions heat is transferred via liquid and gas phase transitions of a fluid sealed inside the pipe. The dissipation portion dissipates heat to the surroundings of the LED lamp via natural or forced convection.
A disadvantage of the LED lamp disclosed in US-A 2006/001384 A1 is in its rather complex and hence expensive facility for removing heat from the LED chips.